Available Online at www.ijcsmc.com International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology ISSN 2320–088X IJCSMC, Vol. 2, Issue. 7, July 2013, pg.262 – 272 RESEARCH ARTICLE © 2013, IJCSMC All Rights Reserved 262 Enhance Luhn Algorithm for Validation of Credit Cards Numbers Khalid Waleed Hussein 1 , Dr. Nor Fazlida Mohd. Sani 2 , Professor Dr. Ramlan Mahmod 3 , Dr. Mohd. Taufik Abdullah 4 1-4 Faculty Computer Science & IT, University Putra Malaysia (UPM), Kuala Lumpur-Malaysia 1 Khaled_it77@yahoo.com, 2 fazlida@fsktm.upm.edu.my, 3 ramlan@fsktm.upm.edu.my, 4 mtaufik@fsktm.upm.edu.my Abstract-The Luhn algorithm is the first line of defense in many e-commerce sites and is used to validate a variety of identification numbers such as credit card numbers. Nevertheless, many card numbers exist and at such volumes, the algorithm cannot distinguish among these numbers. A variety of tests show that the Luhn algorithm suffers from weaknesses including the failure to determine the length and type of credit card number being analyzed. We intend to enhance the Luhn algorithm for the validation of credit card numbers. The enhancement is expected to be useful for many e-commerce sites that use the algorithm. Keyword- Security; Luhn algorithm; Credit Card Number Validation; Visa card Validation; JCB number Validation. I. INTRODUCTION Credit cards are the most frequently used payment method, accounting for about 95% of all online transactions; these are the primary means of payment for goods and services purchased online[1]. With increasing credit card use on the Internet comes a dramatic increase in credit card fraud[2]. Typing errors are one of the most common errors that occur when a user attempts to retype his/her credit card number